Hitachi Koki Co., Ltd.

Hitachi, Ltd.

Masato Yamada

Kazuo Uno

Junji Shirakawa

Takao Kumasaka

Teruaki Mitsuya

Nobuyoshi Hoshi

Yasuo Takuma

Yuzuru Simazaki

Shinichi Nishino

Junji Kobayashi

Shigetaka Fujiwara

Yasuo Takano

Kensei Hosoya

Hiroyoshi Tokoro

Toshimitsu Harada

Kimio Nakamura

Junzi Shirakawa

A transfer apparatus for electrophotography is disclosed in which the resistance values of a transfer belt and the recording paper are measured, and the current value applied to a device for charging a member is set on the basis of the electrical resistance values. The charging device of the transfer belt is adapted to be taken up and reeled out and to circulate along a track. This configuration assures a stable transfer characteristic against the secular environmental variations of the component elements, lengthens the intervals of replacement of the charged member, and hence increases the mechanical life of the transfer apparatus and the electrophotographic apparatus using the same.

Corona deterioration and moisture compensation for transfer unit in an

A xerographic printing machine with at least two rollers disposed so that their axes are arranged parallel to each other. An endless belt, supported by the rollers, has a volume resistance within the range of 10.sup.9 to 10.sup.14 .OMEGA.cm. A photoreceptor is disposed adjacent to the endless belt. An endless belt charging device is disposed opposed to the photoreceptor in such a way that the endless belt is located between the endless belt charging device and the photoreceptor. An electrostatically charged toner supported on the surface of the photoreceptor is transferred to a print media. A guide member is disposed between the photoreceptor and the roller located upstream of the endless belt as viewed in the advancing direction of the endless belt. The guide device guides the advancing print media to bring the print media into contact with the endless belt.

Xerographic printing machine with an improved transfer unit

A transfer unit for a xerographic printing machine including at least two rollers and an endless belt supported by the rollers. A frame member supports the rollers. A photoreceptor is disposed adjacent to the endless belt, and a charging means is disposed opposite to the photoreceptor so that the endless belt is locate between the charging means and the photoreceptor. Pressure in the space within the transfer unit, which is surrounded by the endless belt and the frame member and contains the endless belt charging means disposed therein, is slightly higher than atmosphere pressure outside the transfer unit.

Transfer unit for xerographic printing machine with constant ventilating

In an electrophotographic printing machine, the endless belt has a thin protective layer on each of the inner and outer surfaces thereof which is high in mold release characteristic and effective in minimization of the deterioration in electrical characteristic of the endless belt.

Thin layer coated endless belt of an electrophotographic printing machine

A flash lamp apparatus for reducing occurrence of spots on a recording paper wherein an overlapping portion formed between two adjacent fusing areas of the recording paper receives a first flash and a second flash from a flash lamp so as to heat and fuse a toner on the recording paper. The overlapping portion is controlled so as to reduce occurrence of spots on the recording paper by reducing an area of the overlapping portion on a recording paper. Such reduction in the overlapping portion may be obtained by controlling a frequency of the flash or controlling a feeding velocity of the recording paper. Alternatively, the fusing energy of the overlapping portion may be reduced by changing alternately the radiating energy.

Flash fusing apparatus for reducing occurrence of spots on recording

In an electrophotographic developing device, its doctor blade disposed adjacent to a magnetic roll so as to control the thickness of a layer of magnetic developing agent conveyed by the magnetic roll has an edge which is curved in such a manner that the gap between the edge and the magnetic roll is a minimum in the vicinity of the middle of the magnetic roll, whereby the layer of magnetic developing agent is made uniform in thickness and the printing density is made uniform despite gravitational sagging of the roll.

Electrophotographic developing device having a shaped doctor board

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Ibaraki, Japan

Masato Yamada